This invention relates to a motor driven by pressurized gas and operating in a linear direction and is suitable for metal working such as punching and high velocity cropping. The motor is also suitable for other types of impact work such as forging and metal powder compacting.
One problem associated with machines of this type is the absorption of the kinetic energy of the hammer piston generated by impacts under non-load conditions and the absorption of the kinetic energy which remains in the hammer piston at the end of the work stroke. Previous solutions of this problem propose an arrangement of energy absorbing elements in the stationary part of the tool upon which the movable part of the tool strikes. Such energy absorption causes the tool to be subjected to very high stresses with consequent shortening of the life of the tool. Therefore, the tool costs will be very high especially as such a tool is more complicated than a tool without energy absorbing elements.
This invention proposes to solve this problem by providing a motor which comprises an energy absorbing device by means of which the tool is protected from inadvertently severe impacts.